JEE Mains · Maths · STD 11 - 6. permutation and combination
The total number of three-digit numbers, divisible by \(3\) , which can be formed using the digits \(1,3,5,8\) , if repetition of digits is allowed, is:
- A \(22\)
- B \(18\)
- C \(21\)
- D \(20\)
Answer & Solution
Correct Answer
(A) \(22\)
Step-by-step Solution
Detailed explanation
\((1,1,1) \quad(3,3,3) \quad(5,5,5) \quad(8,8,8)\) \((5,5,8) \quad(8,8,5) \quad(1,3,5) \quad(1,3,8)\) \(\text { Total number }=1+1+1+1+\frac{3 !}{2 !}+\frac{3 !}{2 !}+3 !+3 !=22\)
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